Les Houches

Chair: Veronica Sanz (VH), Christoph Englert (HH)

Members: Fawzi Boudjema, Adam Falkowski, Benjamin Fuks, Florian Goertz, Jose Santiago, Jose Miguel No, Felix Yu, Adam Martin, Ciaran Williams, Ken Mimasu, Alexandra Oliveira, Alberto Tonero, Andrey Katz. Please add your name if it is missing.

Topics for discussion VH:

• Analyses
  1. ATLAS: VH(→ bb) in http://arxiv.org/pdf/1409.6212.pdf
  2. ATLAS: VH(→WW) https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CONFNOTES/ATLAS-CONF-2015-005/
  3. CMS:VH(→bb) https://twiki.cern.ch/twiki/bin/view/CMSPublic/Hig13012PubTWiki and legacy paper https://twiki.cern.ch/twiki/bin/view/CMSPublic/Hig14009PaperTwiki

• SM contributions to VH at one loop: Fawzi to dig old works on this. recast some one-loop V^3 into h V^2
• tree-level:
  1. Dilaton, radion exchange: Matching in http://arxiv.org/pdf/1502.07352.pdf. Ken for form factora.
  2. Composite Higgs type spin-one exchange Adam M., Cedric, Andrey, Adam F., Florian. Model with a custodial triplet is proposed e.g. 1406.7320. It predicts large S, so one may need to tweak it to obtain a realistic (fine-tuned) model with a light resonance.
• one-loop:
  1. 2HDM: Matching in http://arxiv.org/pdf/1502.07352.pdf. Ken
  2. Colored scalars: region of cancellations in gg→ h can be seen in Eq.18 of http://arxiv.org/pdf/1207.7355.pdf, see also http://arxiv.org/pdf/1312.3317.pdf. Matching colored scalars with EFT in http://arxiv.org/pdf/1412.1837v1.pdf and http://arxiv.org/pdf/1504.02409.pdf for non-degenerate stops. Adam M and Felix Andrey
  3. Spin-one: From Composite-Higgs type. Alexandra O.
     1. Not possible from MC point of view, I understood that is maybe non relevant in kinematics point of view, it would act like more terms to the renormalization of three level coupling
• Pseudo-Observables: VS, FB
• Presentation of results together with the HXSWG, feducial cross sections: VS, CPE

Topics for discussion HH:

1. How big can pp>HH be in concrete UV scenarios
   • colored scalars (recast MSSM?) : region of cancellations in gg→ h can be seen in Eq.18 of http://arxiv.org/pdf/1207.7355.pdf, see also http://arxiv.org/pdf/1312.3317.pdf. Matching colored scalars with EFT in http://arxiv.org/pdf/1412.1837v1.pdf and http://arxiv.org/pdf/1504.02409.pdf for non-degenerate stops. VS, FY + BSM
   • 2HDM : Matching of the c_6 to 2HDM is in http://arxiv.org/pdf/1502.07352.pdf, Eq 3.41, and Eq. 3.28 in the alignment limit. CPE, BF
   • Scalar fourplet of SU(2)_L only induces c_6 at the tree level (see e.g. http://arxiv.org/abs/1412.8480): FG
   • Setup without relevant operator (mu^2=0) → large enhancement of pp>HH (factor 2-3), http://arxiv.org/pdf/1504.00355v2.pdf: FG
2. What is the EFT parameter range expected from such scenarios (→ deliverable: c_6 vs Lambda contour plot) CD (composite Higgs), JN (2HDM), CPE, FG
3. How much can we learn from binned distribution at a small expected signal yield (→ deliverable: compare differential distributions for H>hh (with m_H large) and EFT, binned log-likelihood hypothesis test to quantify consistency)
   • 5 parameters EFT scan translated to 2D kinematics to set experimental benchmarks https://twiki.cern.ch/twiki/bin/view/Sandbox/NonResonantHHAtLHC
   • Allow combination of different channels by coordinating bins/benchmarks
4. Backgrounds in HH
   • mass resolution of Higgs tagging (CP and CPE)
     • Can we control Z>bbar (→ deliverable: estimate, simulate or dig out expected resolution)
     • can we disentangle dim 6 effects from qq>HZ leakage